The present invention relates to a method of and an arrangement for treating fish material to make the same ready for consumption in general, and more particularly to salting and/or pickling and/or flavoring and tenderizing such fish material.
There are already known various methods of preparing fish for consumption, among them pickling, salting, or marinating the fish, whether in the form of whole fish or fish pieces of fish fillet. When the methods which have been specifically mentioned above are resorted to, the fish material is immersed in a flavoring bath including, for instance, salt and/or vinegar and/or other flavoring agents, such as carrots, onions, sugar, pepper, bay leaves or the corresponding essences. The fish material is kept in the flavoring bath for an extended period of time during which the flavoring bath penetrates into the tissue of the fish material and not only flavors the same, but also tenderizes such tissue. Because of the need for extending the period of treatment of the fish material by the flavoring bath over several days in the case of pickling or even over several weeks in the case of salting, these prior-art methods call for substantial expenditures not only in the terms of time involved, but also in the terms of equipment needed for accommodating the fish material immersed in the flavoring bath, and additionally also in terms of operating expenses inasmuch as the pickling or salting process must be constantly supervised and any deviations of the properties of the flavoring bath from the desired values must be promptly remedied.
It has been already proposed to somewhat expedite the above-discussed method by treating the fish material in the above-discussed manner but at an elevated temperature. However, it will be appreciated that the treatment at the elevated temperature increases the danger that the fish material may deteriorate or rot during the treatment thereof, particularly inasmuch as these elevated temperatures are conducive to the growth of mildew, fungi, bacteria and the like. Also, the considerably long treatment period brings about substantial losses in weight of fish material which may amount, depending on the fish material being treated, up to 27% of the original weight. A further disadvantage of these prior-art methods is that the possibilities of automation or mechanization of the treatment and further handling of the fish material are quite limited, especially in view of the substantial dwell times of the fish material in the flavoring bath which is needed for accomplishing the proper consistency and taste of the fish material.
Also, as a further disadvantageous result of the long treatment period, the possibilities of establishing, on a short-term basis, the best way of treating the fish material which is then available, for instance, by varying the treatment period, the composition of the flavoring bath, or the temperature at which the fish material is being treated, are very limited, being available only in a few exceptional cases so that the quality of the final product, that is, the treated fish material, will be almost exclusively determined by the experiences of the operating personnel and, therefore, it is very difficult, if not impossible to designedly influence the treatment processes.
On the other hand, it is also already known to improve the tenderness of meat by letting ultrasonic sound energy act thereon. In this connection, it has been already proposed to let the ultrasonic sound waves act on the meat either directly, or through the intermediary of a contact medium. However, to avoid the danger of losing the meat juices through too high dripping losses or through excessive interchange between the contact medium and the meat tissue, the meat pieces have to be treated in a frozen condition. This, of course, involves substantial expenses and renders this method rather cumbersome.